Geo search in MongoDB?

Question

MongoDB

I'm working on a search for location-based data in MongoDB. For example, there is a list of users and for each the coordinates are indicated in the form of longitude, latitude. It is necessary to sort users depending on the distance to a particular point [longitude, latitude] + display the distance.
I do everything using the built-in geosearch MongoDB + Mongoose like this:

User.aggregate([
{
$geoNear: {
near: [latitude, longitude],
distanceField: "distance",
distanceMultiplier: 1000*1000,
maxDistance: 1/111.12,
spherical:true
}
}
]);

Everything seems to be working, but I just can’t figure out how distanceMultiplier, maxDistance works. I need to search for users within a radius of, say, 500 meters and display the distance in meters.
Please tell me what numbers to substitute and how these parameters work.
Thank you.

Answer 1

var maxDistance = Number(query.distance);
  var limit = Number(query.limit);
  var page = Math.max(0, query.page);

  var loc = [];
  loc[0] = Number(query.lon);
  loc[1] = Number(query.lat);

  User.find({
      loc: {
        $near: loc,
        $maxDistance: maxDistance
      }
    }).limit(limit).skip(limit * page).sort({username: 'asc'}).exec(function(err, locations) {
            // ....
    });


    // User schema
   /*
     ....
     loc: {
       type: [Number],
       index: '2d'
     }
     ....
   */